Sound box



,SOUND Box Filed July le, i923 ARTHUR FREDERGK RKCHMOND vrafrnnr COTTGN, OF LONDON, ELllTGraril'uTDA SOUND BOX.

Application filed July 15,"

To ZZ whom it may concern:

Be it known tha l, ARTHUR Fininrinicii RICHMOND COTTON, a subject of the King of England, and residing at 9 l/Jetherliiy Gardens, London, S. lV. L, England, havel invented certain new and useful mproveineiits in Sound Boxes, oi which the fol lowing is a specilication.

rlhis invention relates to grainophones and the like, and consists of an improved construction oi sound-boilr 'for such instruments.

The invention has for object to provide a simple and secure pivotal mounting of the stylus lever, with a minimum of nietallic connection between the latter and the body oi' the sound-box, the lever being held in place by means o'l the control springs;

According to this invention, the stylus lever is provided with an apertured base or plate, which rocks together with the stylus lever upon knife-edges or points mounted upon the rim oi the. sound-box, the plate beingl held in contact with said knifeedges or points by means ol' leert-springs, preferably laminated and constructed of whalebcne, which are litted in the apertures in the plate and secured at their centres against the rim of the sound-box, the springs bearing upon the sides of the plate at the opposite ends of the apertures so as to control the rocking motion of the plate and stylus lever.

rlhe invention has also for object to provide the sound-box with a resonating chainber, which absorbs any harsh notes set up in worn records and also gives increased detail in orchestral music.

The accompanying drawings illustrate the preferred construction of the sound-box:-

Figure 1 is a front elevation.

Figure 2 is a side view in section on the line 2-2 oi Figure 1.

Figures 3 and l represent in section and plan respectively the stylus lever and its apertured base plate.

The sound-box is shown comprising a body formed by the assembly o'l a number oi" coaxial plates or sections; of these, the aluminum plate 1() having a boss 11, lined with a rubber ring 12 is adapted to slide upon the swan-neck or equivalent extremity ci' the tone-arm, shown in dotted lines in Figure 2. The plate is attached by screws 13 to a recessed brass plate 111:, a disc 15 of black vulcanized libre being inter- 1923. Serial No. 651,807.

posed to prevent metallic resonance. The front or end plate 16 attached by screws 17 to the opposite side ofthe plate lcarries the mica or other diaphragm 18 held at its periphery between solid rubber rings 19, E20 ci rectangular section.

The plate 1li has an annular recess 21 upon its forward `lace, this recess being covered by a second diaphragm 2:2 ci' annular shape, held at its outer periphery by the pressure of the rubber ring 2O against the plate 14:, and gripped around its inner periphery by the flange 23 of a hollow bush 24: screwing into the centre oi the plate 111. The recess 21 is filled with petroleum jelly, causing it to act as a resonating chamber, which absorbs any harshA notes or scratching ol the record, and gives increased detail in the reproduction of orchestral records.

rlibe stylus lever 01 reed 25 made oit inild steel or other suitable metal, is provided with a brass plate 26, lsecured to the lever in any convenient manner and carrying the usual socket 27 for the needle or stylus 28. rEhe front 16 or open end of the sound-box has a flat facing 29 upon its rim, in which are inserted a pair of knife-edges or points 30 lying approximately in the plane oit' the diaphragm 18, to which the extremity of the lever is secured by a screw 31. The base plate 26 rests upon the points 30 so as to rock thereon duringrthe vibration of' the diaphragm and lever, seatings 32 oi conical forni or J-section (see Figure 3) being formed in the plate 26 to receive the points 30.

Between. the seatings ot the points 230 and on opposite sides of the needle socket: 2", the plate 2G is formed with apertures 33, ill oft approximately rectangular shape, in which are bedded the springs 35, serving to hold the plate against the points 30 and control its vibratory movement. 'lhese springs are preferably made of whalebone, in accordance with my vprior United States patent speciiication No. 1509,04?, and composed olf a plurality of laminations or leaves; the centr ot the springs are secured against the lacing 2l) by screws 36 and their extremiti-es bear upon the sides oi the plaie 26 at the yends of the apertures 33 the bowed portions near the centres of the springe bedi I un) dine' down into the a Dei-tures of the base 1 t: T" plate, as shown in n igure 2.

l-iavino thus described 1n 1 invention what .D a l claim is said stylus lever,

l. A sound-box, Comprising a body, a dia-l phragm mounted therein, a stylus lever roekably mounted upon said body and connected to said diaphragm, a base plate connected to said stylus lever, said base plate formed with apertures, and control springs secured to said body, said springs itting in said apertures and pressing upon said base plate at opposite sides ofthe axis of its roolring movement.

. 2. A sound-box comprising' il. body, a diaphragm mounted therein,`a stylus lever connected to said diaphragm, pivots lmounted upon said body, a base plate connected to said plate resting upon said pivots, and springs holding said plate in Contact. with said pivots, lsaid springs fitting in apertures in said plate and pressing upon said base plate at opposite sides of the axis of said pivots.

3. sound-box comprising a body, a diaphragm mounted therein, a stylus lever connected to said diaphragm, pivot-s mounted upon said body, a base plate connected to said stylus lever, said plate resting upon said pivots, springs holding said plate in Contact with said pivots, said springs fitting in apertures in said base plate, and means for securing the centres of said springs to said body, the extremities of said springs engaging the sides of said base plate at. opposite ends of said apertures and adapted to control the rocking motion of said lever.

4. In a gramophone sound-box, a stylus lever comprising an arm, means for connecting said arm to the diaphragm, a base plate connected to said lever pivots for rocking movement of said plate, said pivots being aligned approximately in the plane of the diaphragm, means for securing a needle to the base plate, said base pla-te being formed with apertures ot' approximately rectangular shape located symmetrically on either side o1 said needle securing means aud ezitending across the axis on which said plate is adapted to rooli, laminated springs spanning said apertures, and means for securing the centres of said springs to said body, said springs controlling the roc-king motion of said lever.

ARTHUR FREDERICK RICHMOND COTTON. 

